Improved electro-magnetic low-water detecter for steam-boilers



`and close the circuit,

ltnttd gatita WRIGHT DURYEA, OF GLEN COVE, NEW YORK. i

Letters Patent No. 106,142, (lated August 9, 1870.

IMPROVED ELECTRO-MAGNETIC LOW-WATER DETECTER FOR STEAM-BOILERS.

The Schedule referred to in these Letters Patent and making part of the lama To all whom it may concern Bc it known lthat I, WRIGHT DURYEA, of Glen Cove, in dthecounty of Queens and State of New York, have invented a new and useful Improvement in Electro-magnetic Low-water Detecters or AAlarms for Steam-Boilers, of 'which the following is a full, clear, and exact description, reference being .had to the accompanying drawing forming part of' this specificau tion, and iu which- I Figure 1 represents a vertical section of my improvement, as applied to a steam-boiler.

In carrying out this improvement, I propose to use any suitable apparatus through which au electro-magnet may be made to give either an audible or visible alarm, but preferably one of soundgsuch', for instance, as the calls used intelegraph ollices, or the so-called tire-alarms, or bmtglar-alarms, such apparatus being set in operation by making the fallof the water in the boiler, below the levebdctermined upon for safety, act upon a circuitcloser inthe electric circuit in which such electro-magneticapparatus is placed.

This improvement relates more particularly to the manner and means through which the rise and fail ofthe water iu boiler, or in a chamber or vessel in steam and water communication withthe boiler, are made to open The agency which I employ is the expansion and contraction of metals, by variatious in temperature, at an opening provided in the electric circuitat some point within the boiler'itself, or within some attach meut thereto, in which the proceed to describe that form` which I consider the sim plest or ,most preferable.

Referring tothe accompanying drawing- A is a metal pipe, arranged to extendany convenient height above the boiler, or proper water-level therein, outside of the boiler, and connected, ina steam-tight manner, with the boiler, by a screw-coupling, B, which serves, also, to secure or lhold au extension pipe, A, that is open at its bottom, and descends te the level of the water determined upon for safety within tbe boiler.

These pipes A A' are virtually one, the upper section, A, of' which carries, at or near its top, through a suitable screw-couplingl or connection, C, and diaphragm or flange, D, impervious alike to steam and ,-vater, a tube, E, of glass, or other suitable material, arranged so as to be iieely exposed, for a large portion oi' its length, to the space in the pipe A below the diaphragm I), and closed at its bottom.

Nithin thistube E, or pocket, as it may be termed, is a Siphon-shaped tube, F, made of glass, or-other suitable insulating material, and partly filled with quicksilver.

G G are the end portion of the wires in the break of the circuit.

These wire termini pass through a suitable insulating filling or stopper, H, in the upper portion of the tube E, into the two legs, respectively, of the siplion tube, the shorter, and both legs of which, it' necessary, are hermetieally sealed.

The one G of'said wires is, preferably, in constant con tact with the quicksilver in the shorter leg of the siphou F, while the other'wire, G', remains free froni contact with the quicksilverin the longer leg of the siphon, excepting upon exposure of the pocket or tube E to steam heat,as produced by the lling of' the pipe or pipes A A with steam, from within the boiler, by the water falling below the level of' the bottom end oi' the pipe-section A', when the increased temperature communicated to the q'uicksilver causes it to expand and establish contact with the wire G', which closes the circuit, and, by means of the apparatus hereiubefore referred to, causes the necessary alarm or signal to be made which indicates that the water has fallen below its properlevel in the boiler. Said alarm or signal may he at any desired distance from the boiler.

vVhen the water in the boiler rises above the lower end of the pipe-section A', the exposure oi' the pipesection A to the air ou the outside of the boiler will .cause water to be forced, by the pressure of, the steam in the boiler, up the pipe A A', and the temperature in the section A will be lowered, causing the Quicksilver iu the tube F to contract and i'rce itselt ,from vcontact with the wires'G', thus 'breaking the.

circuit again.

It" necessary, there may be a pet-cock or smallleak connected with the pipe-section A, ,at or near its top, to provide for expulsion of the air contained in said section; or such pipe may be suiliciently long or elevated, and the tubes E and Ibe projected a sullicient distance down within said pipe, to dispense with such provision. v

The 'saule principle of action as herein described may be carried out with a solid metallic medium in the place of the Quicksilver or iiuid one, and, when Quicksilver is used, it is not absolutely necessary that the tube containing it should be of siphou form, nor yet that the same should be surrounded by an outer tube, E; thus the opening`l and closing ofuthe circuit may be provided for by means of a tube like that ot a thermometer, partly filled with Quicksilver, and ilse one oi' the wircs termini in the break oi' the circuitI be inserted into the,l end ot' the tube which corresponds with the bulbI ci' the thermometer, and with which the quicksilveris always in Contact, while the other of the wires tenmini is inserted in or through theopposite end ci';said-tube, which should be so arrangedat a suitabieplace in the b'oiler, or in some. i attachment at the proper level, thatit will be exposed 13o the action of water when the level is high enongb, Y and to the action of steam when the level is too low, than; the' qneksilver will be so expanded, in the latter case, as to close the circuit, and so contracted, in the ranged within n steznn-boiler, or its connections, for

operation, by the dili'erenee of temperaturetot' the steam and water therein, in connection with :in eier:- tro-magnetie alarm or signal, substantially as and for the purpose herein set forth.

2. The combination of the wire termini G G' in the break of the cireuit, the Siphon tube F, containing qnieksilver, the outer tube-E, and the pipe or pipes A A', arranged for opemtion in connection with the boiler and vwith an electro-magnetic alarm or signal, essentially as specified.

Witnesses I FRED. HAYNES, Fam). TUSGH.

WRIGHT DURYEA 

